The eRTG system consists of an electric telescopic arm with a current collector trolley that enables automatic retraction and extension into the conductor rail system. The system is available in two versions. The "2+2" version features two conductor systems next to each other, while the Trimotion version features four conductor systems in a row
Both systems have sensors to ensure automatic retraction/extension and steering. A synchronization unit allows seamless switching from diesel power to mains power.